Aerosol-generating system and method of dispensing liquid aerosol-forming substrate with pumped air

ABSTRACT

An aerosol-generating system may include a liquid storage portion, a vaporizer, and a pump. The liquid storage portion may be configured to store a liquid aerosol-forming substrate. The vaporizer may be configured to volatilize the liquid aerosol-forming substrate. The pump may be configured to pump air into the liquid storage portion so as to push out a volume of the liquid aerosol-forming substrate from the liquid storage portion and to supply the volume of the liquid aerosol-forming substrate to the vaporizer. A method for generating an aerosol may be performed with the system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 16/875,355, filedMay 15, 2020, which is a continuation of U.S. application Ser. No.15/825,584, filed Nov. 29, 2017, which is a continuation of and claimspriority to PCT/EP2017/077676, filed on Oct. 27, 2017, and furtherclaims priority to EP 16201201.7, filed on Nov. 29, 2016, thedisclosures of each of which are incorporated herein by reference intheir entirety.

BACKGROUND Field

Example embodiments relate to aerosol-generating systems (which may alsobe referred to as electronic vaping systems), including handheldelectrically operated aerosol-generating systems in which theaerosol-forming substrate is liquid and contained in a liquid storageportion.

Description of Related Art

Aerosol-generating systems may comprise an aerosol-generating device andan aerosol-generating article incorporating a liquid storage portion forstoring a liquid aerosol-forming substrate. The aerosol-generatingdevice may comprise a pump and a vaporizer. During the operation of suchan aerosol-generating system, the pump receives the liquidaerosol-forming substrate from the liquid storage portion and pumps thereceived liquid aerosol-forming substrate to the vaporizer. Thevaporizer applies heat to the liquid aerosol-forming substrate by aheater. By heating the liquid aerosol-forming substrate, an aerosol isgenerated.

The orientation of the aerosol-generating system may vary during itsoperation. Depending on the orientation, air bubbles may be suckedthrough the pump. In such a case, undesired bursts of liquidaerosol-forming substrate may be delivered to the vaporizer. Thus, thevolume of aerosol generated by the vaporizer may vary per pumpactivation and may differ from a desired quantity. Moreover, over thelong term, the pump may be damaged by the pumped air bubbles due tocavity pitting, its performance may deteriorate, and its lifetime may bereduced. A liquid aerosol-forming substrate may be relatively viscous.However, the pumps commercially available for use in aerosol-generatingsystems may have been designed for other purposes (e.g., for pumpingwater-based solutions which are in a range of 10 to 500 times more fluidand less viscous than liquid aerosol-forming substrates foraerosol-generating systems). Thus, pumping a relatively viscous liquidaerosol-forming substrate and supplying a volume of such a liquid maypresent challenges for such a pump. Moreover, the lifetime of the pumpmay be adversely affected from pumping a relatively viscous liquidaerosol-forming substrate instead of a water-based solution.

SUMMARY

An aerosol-generating system may comprise a liquid storage portion, avaporizer, and a pump. The liquid storage portion is configured to storea liquid aerosol-forming substrate. The vaporizer is configured tovolatilize the liquid aerosol-forming substrate. The pump may beconfigured to pump an incoming volume of air into the liquid storageportion so as to displace an outgoing volume of the liquidaerosol-forming substrate from the liquid storage portion and to supplythe outgoing volume of the liquid aerosol-forming substrate to thevaporizer.

The pump may be arranged upstream from the liquid storage portion.

The pump may be a micro-pump configured to pump the incoming volume ofthe air and to displace the outgoing volume of the liquidaerosol-forming substrate per pump activation.

The pump may be configured such that only air enters the pump during thepump activation.

The vaporizer may include a heater configured to heat the outgoingvolume of the liquid aerosol-forming substrate.

The aerosol-generating system may further comprise a main body defininga chamber into which the outgoing volume of the liquid aerosol-formingsubstrate is supplied. The heater may be arranged inside the chamberdownstream from an outlet of the liquid storage portion.

The aerosol-generating system may further comprise an outlet tube influidic communication with the liquid storage portion. The outlet tubemay have an open end configured to direct the supply of the outgoingvolume of the liquid aerosol-forming substrate from the liquid storageportion to the vaporizer.

The liquid storage portion may include a collecting section and aninhibiting section. The collecting section may be configured to collectthe incoming volume of the air from the pump. The inhibiting section maybe configured to inhibit the incoming volume of the air from passing tothe vaporizer.

The collecting section and the inhibiting section may be in a form of aseparating unit configured to separate the liquid storage portion into afirst storage volume and a second storage volume. The first storagevolume may be coupled to the pump. The second storage volume may becoupled to the vaporizer. The separating unit may be configured topermit a passage of the liquid aerosol-forming substrate and to inhibita passage of the incoming volume of the air from the first storagevolume to the second storage volume.

The liquid storage portion may be configured to be coupled to at leastone of the pump and the vaporizer by a coupling so as to be hermeticallysealed.

A method for generating an aerosol may comprise storing a liquidaerosol-forming substrate in a liquid storage portion of anaerosol-generating system. The method may additionally comprise pumpingan incoming volume of air into the liquid storage portion to displace anoutgoing volume of the liquid aerosol-forming substrate from the liquidstorage portion to a vaporizer of the aerosol-generating system. Themethod may further comprise volatilizing the outgoing volume of theliquid aerosol-forming substrate with the vaporizer.

The pumping of the incoming volume of the air to displace the outgoingvolume of the liquid aerosol-forming substrate may be performed per pumpactivation with a micro-pump.

The pumping may be performed such that the outgoing volume of the liquidaerosol-forming substrate is free of air bubbles.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the non-limiting embodimentsherein may become more apparent upon review of the detailed descriptionin conjunction with the accompanying drawings. The accompanying drawingsare merely provided for illustrative purposes and should not beinterpreted to limit the scope of the claims. The accompanying drawingsare not to be considered as drawn to scale unless explicitly noted. Forpurposes of clarity, various dimensions of the drawings may have beenexaggerated.

FIG. 1A and FIG. 1B are schematic views of an aerosol-generating systemin accordance with an example embodiment.

FIG. 2 is a cross-sectional view of a liquid storage portion of anaerosol-generating system in accordance with an example embodiment.

DETAILED DESCRIPTION

It should be understood that when an element or layer is referred to asbeing “on,” “connected to,” “coupled to,” or “covering” another elementor layer, it may be directly on, connected to, coupled to, or coveringthe other element or layer or intervening elements or layers may bepresent. In contrast, when an element is referred to as being “directlyon,” “directly connected to,” or “directly coupled to” another elementor layer, there are no intervening elements or layers present. Likenumbers refer to like elements throughout the specification. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items.

It should be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers, and/or sections should not be limited by these terms. Theseterms are only used to distinguish one element, component, region,layer, or section from another region, layer, or section. Thus, a firstelement, component, region, layer, or section discussed below could betermed a second element, component, region, layer, or section withoutdeparting from the teachings of example embodiments.

Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,”“upper,” and the like) may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It should be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” may encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The terminology used herein is for the purpose of describing variousembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an,” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“includes,” “including,” “comprises,” and/or “comprising,” when used inthis specification, specify the presence of stated features, integers,steps, operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of exampleembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, example embodiments should not be construed aslimited to the shapes of regions illustrated herein but are to includedeviations in shapes that result, for example, from manufacturing.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, including those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Unless specifically stated otherwise, or as is apparent from thediscussion, terms such as “processing” or “computing” or “calculating”or “determining” or “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical, electronicquantities within the computer system's registers and memories intoother data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission or display devices.

In the following description, illustrative embodiments may be describedwith reference to acts and symbolic representations of operations (e.g.,in the form of flow charts, flow diagrams, data flow diagrams, structurediagrams, block diagrams, etc.) that may be implemented as programmodules or functional processes including routines, programs, objects,components, data structures, etc., that perform particular tasks orimplement particular abstract data types. The operations be implementedusing existing hardware in existing electronic systems, such as one ormore microprocessors, Central Processing Units (CPUs), digital signalprocessors (DSPs), application-specific-integrated-circuits (ASICs),SoCs, field programmable gate arrays (FPGAs), computers, or the like.

One or more example embodiments may be (or include) hardware, firmware,hardware executing software, or any combination thereof. Such hardwaremay include one or more microprocessors, CPUs, SoCs, DSPs, ASICs, FPGAs,computers, or the like, configured as special purpose machines toperform the functions described herein as well as any other well-knownfunctions of these elements. In at least some cases, CPUs, SoCs, DSPs,ASICs and FPGAs may generally be referred to as processing circuits,processors and/or microprocessors.

Although processes may be described with regard to sequentialoperations, many of the operations may be performed in parallel,concurrently or simultaneously. In addition, the order of the operationsmay be re-arranged. A process may be terminated when its operations arecompleted, but may also have additional steps not included in thefigure. A process may correspond to a method, function, procedure,subroutine, subprogram, etc. When a process corresponds to a function,its termination may correspond to a return of the function to thecalling function or the main function.

As disclosed herein, the term “storage medium”, “computer readablestorage medium” or “non-transitory computer readable storage medium,”may represent one or more devices for storing data, including read onlymemory (ROM), random access memory (RAM), magnetic RAM, core memory,magnetic disk storage mediums, optical storage mediums, flash memorydevices and/or other tangible machine readable mediums for storinginformation. The term “computer-readable medium” may include, but is notlimited to, portable or fixed storage devices, optical storage devices,and various other mediums capable of storing, containing or carryinginstruction(s) and/or data.

Furthermore, at least some portions of example embodiments may beimplemented by hardware, software, firmware, middleware, microcode,hardware description languages, or any combination thereof. Whenimplemented in software, firmware, middleware or microcode, the programcode or code segments to perform the necessary tasks may be stored in amachine or computer readable medium such as a computer readable storagemedium. When implemented in software, processor(s), processingcircuit(s), or processing unit(s) may be programmed to perform thenecessary tasks, thereby being transformed into special purposeprocessor(s) or computer(s).

A code segment may represent a procedure, function, subprogram, program,routine, subroutine, module, software package, class, or any combinationof instructions, data structures or program statements. A code segmentmay be coupled to another code segment or a hardware circuit by passingand/or receiving information, data, arguments, parameters or memorycontents. Information, arguments, parameters, data, etc. may be passed,forwarded, or transmitted via any suitable means including memorysharing, message passing, token passing, network transmission, etc.

According to some example embodiments, there is provided anaerosol-generating system (which may also be referred to as anelectronic vaping system) comprising a liquid storage portion forstoring a liquid aerosol-forming substrate, a pump, and a vaporizer. Thevaporizer is configured for volatilizing liquid aerosol-formingsubstrate. The pump is configured for pumping air into the liquidstorage portion to push out a volume of the liquid aerosol-formingsubstrate from the liquid storage portion, and to supply the pushed outvolume of aerosol-forming substrate to the vaporizer.

The pump is configured to push or compress air into the liquid storageportion storing the liquid aerosol-forming substrate. The air pushed orcompressed into the liquid storage portion displaces the liquidaerosol-forming substrate such that a volume of the liquidaerosol-forming substrate is dispensed (e.g., air-bubble free) from theliquid storage portion to the vaporizer. The volume of liquidaerosol-forming substrate dispensed to the vaporizer depends on thevolume of compressed air pumped into the liquid storage portion. In anexample embodiment, the pump is arranged upstream of the liquid storageportion and is not interposed between the liquid storage portion and thevaporizer. Thus, the liquid aerosol-forming substrate is not pumpedthrough the pump in such an instance. Therefore, the problems related topumping a liquid aerosol-forming substrate having a relatively highviscosity through a pump may be mitigated or avoided. As the pump onlypumps air in the above example, the pump will not be damaged by thecavity pitting of air bubbles that may be incorporated in a pumpedliquid depending on the orientation of the aerosol-generating system.Therefore, the aerosol-generating system is capable of reliablydelivering an intended volume of liquid aerosol-forming substrate to thevaporizer and volatilizing the delivered volume of liquidaerosol-forming substrate in a wide range of orientations of theaerosol-generating system (e.g., independent of the orientation of theaerosol-generating system illustrated in the drawings).

The pump may be arranged upstream of the liquid storage portion. As usedherein, the terms “upstream”, “downstream”, “proximal”, “distal”,“front” and “rear”, are used to describe the relative positions ofcomponents, or portions of components, of the aerosol-generating systemin relation to the direction in which a vapor or aerosol flows throughthe aerosol-generating system. The aerosol-generating system maycomprise a mouth end through which an aerosol exits theaerosol-generating system. The mouth end may also be referred to as theproximal end. A negative pressure may be applied to the proximal ormouth end of the aerosol-generating system in order to draw an aerosolfrom the aerosol-generating system. The aerosol-generating systemcomprises a distal end opposite to the proximal or mouth end. Theproximal or mouth end of the aerosol-generating system may also bereferred to as the downstream end. The distal end of theaerosol-generating system may also be referred to as the upstream end.As the pump is arranged upstream of the liquid storage portion, the pumpis arranged closer to the distal end compared to the liquid storageportion. Components, or portions of components, of theaerosol-generating system may be described as being upstream ordownstream of one another based on their relative positions between theproximal, downstream or mouth end and the distal or upstream end of theaerosol-generating system.

The aerosol-generating system may be configured for vaporizing liquidaerosol-forming substrates having a relatively high viscosity ascompared to water. The viscosity of such a liquid aerosol-formingsubstrate may be in the range from about 10 to 500 Millipascal-seconds(e.g., in the range from about 17 to 86 Millipascal-seconds (mPa·s)).

The pump may be configured such that only air enters the pump duringpump activation. Thus, in an example embodiment, no viscous liquidaerosol-forming substrate passes through the pump.

The pump may be a micropump configured to pump a desired orpredetermined volume of air per pump activation.

The pump may be configured to push out a desired or predetermined volumeof the liquid aerosol-forming substrate from the liquid storage portionto the vaporizer per pump activation. The liquid aerosol-formingsubstrate is essentially incompressible such that the volume of theliquid aerosol-forming substrate does not depend upon the pressure ofthe liquid aerosol-forming substrate.

The pump can be tuned for pushing a desired volume of liquidaerosol-forming substrate to the vaporizer. For pushing out a desiredvolume of liquid aerosol-forming substrate from the liquid storageportion, a certain volume of air must be pumped into the liquid storageportion by the pump. The compressed air pumped into the liquid storageportion occupies the volume of the liquid being pushed out from theliquid storage portion by the compressed air. To keep the compressed airat a certain pressure within the liquid storage portion, a one-way valvemay be provided at the inlet of the liquid storage portion. In anexample embodiment, the pump pumps air of constant pressure into theliquid storage portion such that the volume of pumped air corresponds tothe volume of liquid aerosol-forming substrate being pushed out. Thepump may allow an on-demand delivery of liquid-aerosol-forming substrateat a relatively low flow rate of, for example, approximately 0.5 to 2microliters per second for intervals of variable or constant duration.The flow rate of the liquid aerosol-forming substrate delivered to thevaporizer may depend on a pumping frequency of the pump. For achieving adesired flow rate of the liquid aerosol-forming substrate, a suitablepumping frequency of the pump may be determined from a lookup tablestoring a correspondence between specific desirable flow rates andspecific operable pumping frequencies. A desired flow rate of the liquidaerosol-forming substrate may be achieved by appropriately setting oradjusting the pumping frequency based on the lookup table.

In an example embodiment, the aerosol-generating system comprises a tubethrough which the volume of the liquid aerosol-forming substrate issupplied from the liquid storage portion to the vaporizer arrangeddownstream of an open end of the tube.

The tube may be a nozzle. The tube may comprise any appropriatematerial, for example, glass, silicone, metal (e.g., stainless steel),or plastics material (e.g., polyether ether ketone (PEEK)). The size ofthe tube may match that of the outlet of the liquid storage portion. Forexample, the tube may have a diameter of about 1 to 2 millimetres, butother sizes are possible. The tube may be a capillary nozzle having adiameter of about 1 millimeter, for example, a glass nozzle, connectedto the outlet of the liquid storage portion via silicone tubing. Thetube may comprise a capillary tube. The cross-section of the capillarytube may be circular, ellipsoidal, triangular, rectangular, or any othersuitable shape for conveying liquid. At least a width dimension of thecross-sectional area of the capillary tube may be sufficiently smallsuch that capillary forces are present. At the same time, thecross-sectional area of the capillary tube may be sufficiently largesuch that a suitable volume of liquid aerosol-forming substrate can beconveyed to the heating element. The cross-sectional area of thecapillary tube may be below 4 square millimetres (e.g., below 1 squaremillimetre, or below 0.5 square millimetres).

In an example embodiment, the vaporizer comprises a heater for heatingthe supplied volume of liquid aerosol-forming substrate. The heater maybe any device suitable for heating the liquid aerosol-forming substrateand volatilizing at least a part of the liquid aerosol-forming substratein order to form an aerosol. The heater may be a heated coil, a heatedcapillary, a heated mesh, or a heated metal plate. The heater may be aresistive heater which receives electrical power and transforms at leastpart of the received electrical power into heat energy. The heater maycomprise only a single heating element or a plurality of heatingelements. The temperature of the heating element or elements may becontrolled by electronic circuitry.

The vaporizer may comprise, as a heating element, a heating coilextending from the tube in longitudinal direction. The heating coil maybe mounted transverse to the tube. The heating coil may overlap with theopen end of the tube for up to 3 millimetres (e.g., for up to 1millimetre). In some examples, there may be a distance between the openend of the tube and the heating coil. The length of the heating coil maybe 2 millimetres to 9 millimetres (e.g., 3 millimetres to 6millimetres). The diameter of the heating coil may be chosen such thatone end of the heating coil can be mounted around the tube. The diameterof the heating coil may be 1 millimetre to 5 millimetres (e.g., 2millimetres to 4 millimetres).

The vaporizer may comprise, as a heating element, a conical heaterextending from the tube in longitudinal direction. The conical heatermay overlap with the open end of the tube. In some examples, there maybe a distance of 0.1 millimetres to 2 millimetres between the open endof the tube and the conical heater (e.g., 0.1 millimetres to 1millimetre). The slant height of the conical heater may be 2 millimetresto 7 millimetres (e.g., 2.5 millimetres to 5 millimetres). The diameterof the conical heater in a cross-sectional view may increase, whenfollowing the slant height from one end to the other, from a firstdiameter to a second diameter. The first diameter may be 0.1 millimetresto 2 millimetres (e.g., 0.1 millimetres to 1 millimetre). The seconddiameter may be 1.2 millimetres to 3 millimetres (e.g., 1.5 millimetresto 2 millimetres). In a non-limiting embodiment, the conical heater isarranged such that the liquid aerosol-forming substrate exiting from thetube passes the conical heater at the first diameter before the seconddiameter. The first diameter of the conical heater may be chosen suchthat one end of the conical heater can be mounted around the tube.

The vaporizer may comprise, as a heating element, a flat heater with,for example, a solid or mesh surface. Alternatively, the vaporizer maycomprise, as a heating element, a mesh heater. In another instance, thevaporizer may comprise, as a heating element, an arrangement offilaments.

The vaporizer may comprise at least one of a solid, flexible, porous,and perforated substrate onto which the heating element may be, forexample, at least one of mounted, printed, deposited, etched, andlaminated. The substrate may be a polymeric or ceramic substrate.

Both the pump and the heater may be triggered by a puff detectionsystem. Alternatively, the pump and the heater may be triggered bypressing an on-off button, which may be held for a desired duration.

The aerosol-generating system may comprise a chamber into which thevolume of the liquid aerosol-forming substrate is supplied. The heaterof the vaporizer may be arranged inside the chamber downstream of anoutlet of the liquid storage portion.

The liquid storage portion may be configured for storing the liquidaerosol-forming substrate to be supplied to the vaporizer and forreceiving air from the pump. The liquid storage portion may beconfigured as a container or a reservoir for storing the liquidaerosol-forming substrate.

The liquid storage portion may comprise means for collecting the airreceived from the pump and means for inhibiting the air pumped into theliquid storage portion for passage to the vaporizer. In order to preventa reverse flow of the received air back to the pump, the liquid storageportion may comprise a one-way valve as an inlet for receiving air fromthe pump.

The means for collecting the air received from the pump and the meansfor inhibiting the air pumped into the liquid storage portion forpassage to the vaporizer may be a separating unit which separates theliquid storage portion into a first storage volume and second storagevolume. The first storage volume is coupled to the pump for receivingair. The second storage volume is coupled to the vaporizer. Theseparating unit is configured to allow the liquid aerosol-formingsubstrate to pass and to inhibit passage of the air from the first tothe second storage volume. The separating unit may be implemented byproviding within the liquid storage portion at least one dividing wallbetween the first and the second storage volume and at least one gap orvalve (e.g., a one-way valve) for passing liquid aerosol-formingsubstrate essentially without air bubbles from the first to the secondstorage volume. The separating unit may be configured such that the gapor the valve is located below the fill level of the liquidaerosol-forming substrate in the first storage volume over a wide rangeof orientations of the liquid storage portion. In this way, theseparating unit enables air bubble free liquid dispensing over a widerange of orientations of the liquid storage portion.

The liquid storage portion may be configured to be coupled to at leastone of the pump and the vaporizer by a respective coupling so as to behermetically sealed from the surrounding atmosphere. The couplings maybe configured as self-healing pierceable membranes. The membranes mayhinder or avoid undesired leaking of the liquid aerosol-formingsubstrate stored in the liquid storage portion. The liquid storageportion may be configured as a replaceable tank or container. Forcoupling the replaceable liquid storage portion to the pump and/or thevaporizer, a respective needle-like hollow tube may be pierced through arespective membrane. When the pump and/or the vaporizer are coupled tothe liquid storage portion, the membranes may hinder or avoid theundesired leaking of the liquid aerosol-forming substrate and theleaking of air from and into the liquid storage portion.

The aerosol-generating system may comprise a main unit and a cartridge.The cartridge may be removably coupled to the main unit. The main unitmay comprise a power supply. The liquid storage portion may be providedin the cartridge, and the pump may be provided in the main unit. Themain unit may further comprise the vaporizer.

The aerosol-generating system may further comprise electronic circuitryconnected to the vaporizer and to an electrical power source. Theelectronic circuitry may be configured to monitor the electricalresistance of the vaporizer. The electronic circuitry may also beconfigured to control the supply of power to the vaporizer based on theelectrical resistance of the vaporizer.

The electronic circuitry may comprise a controller with amicroprocessor, which may be a programmable microprocessor. Theelectronic circuitry may comprise further electronic components. Theelectronic circuitry may be configured to regulate a supply of power tothe vaporizer. Power may be supplied to the vaporizer continuouslyfollowing activation of the system or may be supplied intermittently,such as on a puff-by-puff basis. The power may be supplied to thevaporizer in the form of pulses of electrical current.

The electronic circuitry may be configured to set or regulate a pumpingfrequency of the pump and/or to control the supply of power to the pump.

The aerosol-generating system may comprise a power supply (e.g., abattery) within the main body of the housing. The power supply may be aform of charge storage device such as a capacitor. The power supply mayrequire recharging and may have a capacity that allows for the storageof enough energy for one or more periods of vapor or aerosol generation.For example, the power supply may have sufficient capacity to allow forthe continuous generation of aerosol for a period of around six minutesor for a period that is a multiple of six minutes. In another example,the power supply may have sufficient capacity to allow for a desired orpredetermined number of puffs or discrete activations of the heaterassembly.

To allow ambient air to enter the aerosol-generating system, a wall ofthe housing of the aerosol-generating system may be provided with atleast one semi-open inlet. The wall of the housing may be opposite tothe vaporizer (e.g., a bottom wall). In a non-limiting embodiment, thesemi-open inlet allows air to enter the aerosol-generating system whilehindering or preventing air or liquid from leaving theaerosol-generating system through the semi-open inlet. A suitablesemi-open inlet may, for example, be a semi-permeable membrane, which ispermeable in one direction only for air, but is air- and liquid-tight inthe opposite direction. A semi-open inlet may, for example, also be aone-way valve. The semi-open inlets may be configured to allow air topass through the inlet only if specific conditions are met (e.g., whenthere is a depression in the aerosol-generating system or a volume ofair passing through the valve or membrane that meets a threshold value).The aerosol-generating system may have an additional air inlet forambient air to be sucked into by the operating pump.

The liquid aerosol-forming substrate is a substrate capable of releasingvolatile compounds that can form an aerosol. The volatile compounds maybe released by heating the liquid aerosol-forming substrate. The liquidaerosol-forming substrate may comprise a plant-based material. Forexample, the liquid aerosol-forming substrate may comprise tobacco. Theliquid aerosol-forming substrate may comprise a tobacco-containingmaterial containing volatile tobacco flavour compounds, which arereleased from the liquid aerosol-forming substrate upon heating. Theliquid aerosol-forming substrate may alternatively comprise anon-tobacco-containing material. The liquid aerosol-forming substratemay comprise homogenised plant-based material. The liquidaerosol-forming substrate may comprise homogenised tobacco material. Theliquid aerosol-forming substrate may comprise at least oneaerosol-former. The liquid aerosol-forming substrate may comprise otheradditives and ingredients, such as flavourants.

The aerosol-generating system may be portable. For example, theaerosol-generating system may have a size comparable to a cigar orcigarette. The aerosol-generating system may have a total length betweenapproximately 30 millimetres and approximately 150 millimetres. Theaerosol-generating system may have an external diameter betweenapproximately 5 millimetres and approximately 30 millimetres.

According to some example embodiments, there is provided a method forgenerating an aerosol. The method may comprise providing a liquidstorage portion for storing a liquid aerosol-forming substrate; pumpingair, by a pump, into the liquid storage portion to push out, by the airpumped into the liquid storage portion, a volume of the liquidaerosol-forming substrate from the liquid storage portion to avaporizer; and volatilizing, by the vaporizer, at least a part of thevolume of the liquid aerosol-forming substrate pushed out from theliquid storage portion.

The volume of the liquid aerosol-forming substrate, in a further step,may be pushed out (e.g., free of air bubbles) from the liquid storageportion to the vaporizer.

The pump may be a micropump and may be configured to pump a desired orpredetermined volume of air per pump activation.

A desired or predetermined volume of the liquid aerosol-formingsubstrate may, in a further step, be pushed out from the liquid storageportion to the vaporizer by one pump activation.

It should be understood that features described in relation to one ormore examples above may equally be applied to other examples herein.

FIG. 1A and FIG. 1B show a schematic illustration of anaerosol-generating system of an example embodiment. Theaerosol-generating system comprises a main unit and a refillable orexchangeable cartridge with a liquid storage portion 5. The liquidstorage portion 5 is configured for storing a liquid aerosol-formingsubstrate. The main unit comprises a main body 10 and a mouthpieceportion 12. The main body 10 contains a power supply 1 (e.g., a batterysuch as a lithium iron phosphate battery), electronic circuitry 2, acavity for holding a cartridge, a micropump 3, and a vaporizer 7.Electrical connectors 8, 9 are provided at the sides of the main body 10to provide an electrical connection between the electronic circuitry 2,the power supply 1, and the vaporizer 7. The micropump 3 is configured,when being operated, to suck air into its inlet and to provide pumpedair at its outlet. Tube 4 is provided to connect the outlet of themicropump 3 to the inlet of the liquid storage portion 5. When themicropump 3 operates, it pumps air via the tube 4, which is airtight tothe environment, to the liquid storage portion 5. The compressed airpumped into the inlet of the liquid storage portion 5 pushes bydisplacement of a volume of liquid aerosol-forming substrate through theoutlet of the liquid storage portion 5 into tube 6. Tube 6 leads theflow of liquid aerosol-forming substrate from the outlet of the liquidstorage portion 5 to the deposition region of the heating element of thevaporizer 7. A rate of the flow of the liquid aerosol-forming substrateis determined by a pumping frequency of the micropump 3. The mouthpieceportion 12 comprises a plurality of air inlets 11 and an outlet 13. Anegative pressure may be applied to the outlet 13 to draw air from theair inlets 11, through the mouthpiece portion 12, and to the outlet 13.Internal baffles may be provided to force the air flowing through themouthpiece portion 12. The vaporizer 7 is configured to heat the liquidaerosol-forming substrate directly after the liquid aerosol-formingsubstrate exits the tube 6.

The cartridge is configured to be received in a cavity within the mainbody 10. The cartridge may be replaced when the aerosol-formingsubstrate provided in the cartridge is depleted. When inserting a newcartridge, a slider at the main body may be moved to expose the cavity.A new cartridge may be inserted into the exposed cavity. The inlet ofthe liquid storage portion 5 is configured to connect to the tube 4connected to the outlet of the micropump 3. The outlet of the liquidstorage portion 5 is configured to connect to the tube 6 connected tothe vaporizer 7. In an example embodiment, the main unit is portable andhas a size comparable to a cigar or cigarette.

FIG. 2 is a cross-sectional view of a liquid storage portion of anaerosol-generating system in accordance with an example embodiment. Theliquid storage portion 5 shown in FIG. 2 corresponds to the liquidstorage portion 5 shown in FIG. 1B. The liquid storage portion 5 isconfigured as a tank or reservoir for storing a liquid aerosol-formingsubstrate 29. The liquid storage portion 5 comprises a housing 20, afirst membrane 27 (e.g., first self-healing pierceable membrane) at thebottom of the housing 20, and a second membrane 28 (e.g., secondself-healing pierceable membrane) at the top of the housing 20. Thehousing 20 and the membranes 27 and 28 define an inner volume of theliquid storage portion 5 that is hermetically sealed from the outerenvironment. The inner volume is divided by a separating unit into afirst storage volume 21 and a second storage volume 22.

In an example embodiment, the separating unit is formed by a firstdividing wall 23 and a second dividing wall 26. The first dividing wall23 extends longitudinally in the direction from the bottom to the top ofthe liquid storage portion 5. The second dividing wall 26 almost fullyseparates the first storage volume 21 and the second storage volume 22from each other except a gap 25 close to the bottom of the liquidstorage portion 5. The first dividing wall 23 and the section of thesecond dividing wall 26 ending at the gap 25 are mounted facing eachother at a distance for defining a vertical gap 24. The vertical gap 24extends longitudinally in the direction from the bottom to the top ofthe liquid storage portion 5. The first storage volume 21 and the secondstorage volume 22 are separated by gap 25 and vertical gap 24 from eachother. A one-way valve (not shown) allowing the liquid aerosol-formingsubstrate 29 to pass from the first storage volume 21 to the secondstorage volume 22 and blocking air from passing to the second storagevolume 22 may be arranged in the vertical gap 24. The first storagevolume 21 is configured for the storing the liquid aerosol-formingsubstrate 29 and a volume of air 30. A portion of the second dividingwall 26 extends longitudinally from the gap 25 in the direction from thebottom to the top of the liquid storage portion 5. The arrangement ofthe second dividing wall 26 establishes in the second storage volume 22a dip tube 33 extending longitudinally in the direction from the bottomto the top of the liquid storage portion 5. The gaps 24, 25 and the diptube 33 are arranged relative to each other such that air bubbles areinhibited from passing from the first storage volume 21 to the secondstorage volume 22 over a wide range of orientations of the liquidstorage portion 5. Thus, only the liquid aerosol-forming substrate 29(without any air bubbles) is stored in the second storage volume 22 overa wide range of orientations. This allows liquid dispensing that is airbubble free over a wide range of orientations of the liquid storageportion 5. The range of orientations may be between 0 and ±90 degreesfor liquid dispensing that is air bubble free. FIG. 2 shows anorientation of approximately 0 degrees according to an exampleembodiment. In the orientation of the liquid storage portion 5 shown inFIG. 2, the outlet of the liquid storage portion 5 is located at thetop, and the inlet is located at the bottom of the liquid storageportion 5 or at least below the fill level. In the desired usageorientation, the dividing wall(s) and the gap(s) ensure that no air 30passes from the first storage volume 21 to the second storage volume 22.Air bubbles may be hindered or prevented from passing into the secondstorage volume 22 if the liquid storage portion 5 is not inclined morethan 90 degrees compared to the upright position depicted in FIG. 2.

The liquid storage portion 5 shown in FIG. 2 may be coupled to themicropump 3 shown in FIG. 1B by piercing an end of tube 31, which maycorrespond to tube 4 of FIG. 1B, through the first self-healingpierceable membrane 27. Furthermore, the liquid storage portion 5 may becoupled to the vaporizer 7 shown in FIG. 1B by piercing an end of tube32, which may correspond to tube 6 of FIG. 1B, through the secondself-healing pierceable membrane 28. For dispensing a volume of liquidaerosol-forming substrate 29 stored in the second storage volume 22through the tube 32 to the vaporizer 7, the micropump 3 pumps airthrough the tube 31 into the first storage volume 21. In response to thepumped air, a volume of liquid aerosol-forming substrate 29 stored inthe first storage volume 21 is displaced through the gaps 24, 25 to thesecond storage volume 22, thus resulting in the dispensing the samevolume of liquid aerosol-forming substrate 29 from the second storagevolume 22 through the tube 32. The air pumped into the liquid storageportion 5 is collected in the first storage volume 21.

While a number of example embodiments have been disclosed herein, itshould be understood that other variations may be possible. Suchvariations are not to be regarded as a departure from the spirit andscope of the present disclosure, and all such modifications as would beobvious to one skilled in the art are intended to be included within thescope of the following claims.

1. An aerosol-generating system, comprising: a storage portioncontaining an aerosol-forming substrate; and a main unit configured topump an incoming volume of air into the storage portion to displace anoutgoing volume of the aerosol-forming substrate from the storageportion and to heat the outgoing volume of the aerosol-forming substrateto generate an aerosol.
 2. The aerosol-generating system of claim 1,wherein the storage portion defines an inlet for the incoming volume ofthe air and an outlet for the outgoing volume of the aerosol-formingsubstrate.
 3. The aerosol-generating system of claim 2, wherein theinlet is the only point of ingress into the storage portion, and theoutlet is the only point of egress from the storage portion.
 4. Theaerosol-generating system of claim 2, wherein the storage portionfurther defines a first storage volume and a second storage volumecontaining the aerosol-forming substrate.
 5. The aerosol-generatingsystem of claim 4, wherein the storage portion includes a first dividingwall and a second dividing wall configured to partition the firststorage volume and the second storage volume.
 6. The aerosol-generatingsystem of claim 5, wherein the first dividing wall and the seconddividing wall are configured inhibit a passage of the incoming volume ofthe air through the storage portion.
 7. The aerosol-generating system ofclaim 5, wherein the first dividing wall and the second dividing wallhave overlapping portions.
 8. The aerosol-generating system of claim 7,wherein the overlapping portions of the first dividing wall and thesecond dividing wall define a gap therebetween.
 9. Theaerosol-generating system of claim 8, wherein the first storage volumeis in fluidic communication with the second storage volume via only thegap.
 10. The aerosol-generating system of claim 4, wherein the storageportion is configured such that the incoming volume of the air isconfined to the first storage volume.
 11. The aerosol-generating systemof claim 4, wherein the main unit is configured to pump the incomingvolume of the air into the first storage volume via the inlet in thestorage portion.
 12. The aerosol-generating system of claim 4, whereinthe storage portion is configured such that the outgoing volume of theaerosol-forming substrate displaced therefrom is from the second storagevolume.
 13. The aerosol-generating system of claim 1, wherein the mainunit includes a micropump upstream from the storage portion, themicropump configured to pump the incoming volume of the air into thestorage portion.
 14. The aerosol-generating system of claim 1, whereinthe main unit includes a vaporizer downstream from the storage portion,the vaporizer configured to heat the outgoing volume of theaerosol-forming substrate.